Refractive surgery and other corrective procedures are commonly performed on the human eye. During a refractive surgical procedure, the refractive quality of the eye is altered. The goal of refractive surgery typically is to correct a defective refractive condition of the eye, while not diminishing the overall refractive quality of the eye. In some cases, the goal is to actually improve the overall refractive quality of the eye.
Refractive measurements are typically taken with phoroptors, pachymeters, corneal topographers, autorefractors, keratometers, and/or wavefront sensors. Of these devices, wavefront sensors generally provide the greatest detail about the refractive condition of, and additional information relating to, the eye. Wavefront sensors are generally standalone devices that operate in relatively large areas dedicated to the use of the wavefront sensors. With most existing wavefront sensors, the patient's eye is measured while the patient is in a sitting position.
Many methods of performing refractive eye surgery require pre-operatively measuring the refractive quality of a patient's eye using a wavefront sensor or other measuring device. This refractive quality information is used to plan a detailed refractive surgical procedure. The patient is then typically moved from the wavefront sensor location to a surgical location, where the patient lies supine in the “surgical position.” During the refractive surgical procedure, the surgeon may view the patient's eye through a surgical microscope or other viewing device, which typically is suspended above the patient's head via a balancing mechanism or other similar device. Once the refractive surgical procedure is completed, the patient is typically moved back to the wavefront sensor location, and the eye is measured to determine the outcome of the surgery.
Although measuring the refractive quality of the eye after the refractive surgery has been performed provides a quantification of the outcome of the surgery, it does not allow modifications to the surgery to be performed while the patient remains in the surgical position. If the outcome is not ideal, the patient may be relocated to the surgical area for a re-treatment, but in many cases a re-treatment may not be as effective as if the procedure had been performed to produce an ideal result the first time before the patient was moved from the surgical position. Additionally, moving a patient out of the sterile surgical field for diagnostic purposes, and then back into the surgical field, can be problematic.
If the refractive quality of the eye could be measured repeatedly as the surgery is progressing, without moving the patient, the surgeon would have the opportunity to judge whether the procedure was producing desired results at the expected rate, and would be able to make adjustments or course corrections to the procedure midstream to improve the likelihood of achieving the desired outcome. Unfortunately, existing wavefront sensors and other measuring devices are generally relatively large and heavy, making them impracticable or impossible to suspend above a patient's head during surgery. As a result, a patient must be physically moved between wavefront measurement procedures and surgical correction procedures that are typically performed under a surgical microscope.
While attempts have been made to integrate a microscope into a comprehensive treatment and measurement device, such devices are typically very large, heavy, and cumbersome, such that they cannot be practically suspended above a patient lying in the surgical position. These devices also typically include shared lenses and other optical components. The sharing of optical components in this manner generally obscures the overall quality of the measurements that are produced, since each device component typically has its own set of optical requirements that cannot each be optimally satisfied using shared lenses and so forth. Thus, a need exists for an improved device for measuring and evaluating refractive and other optical properties and characteristics of an eye.